1. Field of the Invention
The present invention relates generally to mold assemblies for creating countertop products and, more particularly, to an improved assembly for creating a countertop product displaying a built-up edge and a method for producing a countertop utilizing such an assembly.
2. Description of the Prior Art
Mold processes are known in the art for creating finished solid surface countertops. An example of such a process is illustrated in U.S. Pat. No. 5,628,949, issued to Bordener, which teaches a negatively shaped and open countertop mold which is constructed by a plurality of barriers placed in interconnecting fashion atop a flat polished surface. An initial spray of a continuous layer of a high quality resin coating is applied over the exposed top and elevated side surfaces of the mold and, after being permitted to cure for a selected period of time, is backfilled by a first pour of a substrate material over the gelled high quality resin coating. In order to create a desired built-up edge for the countertop additional barriers are constructed atop the substantially gelled first pour and in desired proximity to the edges of the mold enclosure defining barriers. A subsequent layer of substrate material is then poured to fill an outer perimeter channel established between the damming barriers and the enclosure defining barriers. The mold and countertop are then permitted to set and cure for several hours, following which the completely gelled and cured countertop is demounted from the mold by dissassembling the mold barriers.
The Bordener '949 reference teaches a very novel and useful process for producing a solid surface countertop which is an improvement over sheet stock surface products such as Dupont CORIAN or Surell FORMICA which of necessity must be manually cut and fabricated and then surface finished. The disclosure of the Bordener '949 reference is however such that it is fairly limited to the creation of a substantially horizontally oriented and gravity casted mold process construction. The construction of Bordener '949 further requires that a substantial period of cure time be employed prior to demounting the countertop from within the mold and so that the surface of the countertop is fairly completely dried and hardened so as not to be damaged during the demounting procedure.
Additional examples of closed mold assemblies for producing thin-walled plastic articles and the like, and which are unrelated to solid surface countertop technology, are illustrated in U.S. Pat. Nos. 5,064,585, issued to Cooper et al., 4,834,929, issued to Dehoff et al. And 4,208,368, issued to Egli. Cooper teaches a mold with two assembleable halves which meet at a parting plane and which are heated to an elevated temperature prior to receiving a fluidic curable resin at a pressure of at least 4 pounds per square inch. The molding is preferably a thin-walled and rigid plasticized kitchen sink which is produced in high volume.
Dehoff teaches close mold method for making precision and low cost molds, typically plastic panels, which involves the steps of orienting a pattern of a part to be produced on a surface plate and within a molding dam, applying release coating to the surfaces, applying a series thin resin layer, fiber reinforced resin and epoxy-dry plaster bonding layer, inserting a reinforcing framework into the dam and applying a bulk casting plaster to complete the body of the mold. Egli teaches a closable and sealable mold for producing molding articles of expandable plastic. A heated plastic melt material is directed into a mold core within the mold and which proceeds throughout the cavity to fill the area formerly occupied by the core. Venting means are provided for evacuating gas pockets created by the action of the heated plastic dissolving the foam construction core.